Ten key indexing mechanism



April 26, 1955 E. L. WISE TEN KEY INDEXING MECHANISM Filed Dec. 29, 1953 ATTORNEY United States Patent TEN KEY INDEXING MECHANISM Elmer L. Wise, Farmington, Conn., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application December 29, 1953, Serial No. 400,865

Claims. (Cl. 235-145) This invention relates to adding and accounting machines, more particularly to improvements in the ten key keyboard used for indexing amounts in such machines.

Ten key adding machines are well known and are generally so constructed that operation of a key to index an amount must be completed to operate and release an escapement mechanism to enable denominational indexing of an amount set-up device before a second key can be effectively operated. Such operation requires that an operator use a touch substantially different from that used by a skilled typist and does not permit skilled operators to use all of the speed of which they are capable.

It is, then, one object of the present invention to devise an adding machine keyboard which may be operated at a high rate of speed and in which the key touch 18 not substantially different from that of a typewriter.

It is another object of this invention to produce an adding machine keyboard having ten keys, each of which may be effectively operated before a depressed key has begun its return to normal position.

A further object is the development of a ten key adding machine keyboard in which each key performs its complete function on its descending stroke and m which a key may be operated to index an amount even if another key is held depressed or is in its return to normal position.

Other objects will be apparent in the following description of a preferred embodiment of the invention with reference to the accompanying drawings.

In the drawings:

Figure 1 is a right side section of the keyboard and indexing mechanism,

Figure 2 is a top view showing the parts in normal position,

Figure 3 is a top view similar to Figure 2 but showing the parts in the position after a key has been depressed and before it is released, and

Figure 4 is a perspective view showing details of the connection between a key and the indexing mechanism.

The present embodiment of this invention is disclosed as applied to the keyboard of a well known Sundstrand adding machine. This type of machine is generally as set out in U. S. Patents Nos. 1,583,102 and 1,965,611 issued May 4, 1926, and July 10, 1934, respectively, to Oscar J. Sundstrand. The machine disclosed in those patents has a ten key keyboard in which each key is directly connected to a push rod which sets a stop pin and simultaneously operates an escapement push rod Which releases the escapement mechanism for a partial step. On the return of the key, the escapement push rod is released to permit the escapement to make the remainder of its step. In such machines a numeral key cannot be effectively operated until a previously depressed key has been restored to its original position.

The present embodiment provides a keyboard which may be operated at a considerably greater speed than those previously used for there is no need to wait until a previously depressed key has been restored before another key may be depressed, the indexing by a key taking place even if another key is deliberately held depressed.

Referring to Figure 1, the numeral keys are slidably mounted in a pair of plates 11 and 12 and each key has an ear 13 projecting therefrom into engagement with a leg 15 of a bail 16 pivoted in the keyboard side plates 17, see Figure 2. Each bail 16 has connected to it a slide 20 guided at its rear end in a comb 19, see also Figures 2 and 3, secured to the right side wall 17.

Depression of any key will rock its associated bail 16 clockwise to move its slide 20 rearwardly. Pivoted on a stud 21 fixed in base plate 12 is a plurality of levers 22, one for each key, each lever being tensioned clockwise, Figure 2, by a spring 23, see also Figure 4, against a square stud 25 in slides 20 to return the slides 20, bails 16 and keys 10 to the normal, Figure 1, position.

Also pivoted on stud 21 is a plurality of levers 26, one for each key, each lever 26 being tensioned clockwise by a spring 27 to position a left arm of the lever against a stop bar 28 and the right arm just to the rear of square stud 25 in the associated slide 20. Each lever 26 is connected to one end of a push rod 29. Also pivoted on stud 21 is a swinging arm 30, Figure 1, carrying a perforated post 33 at its rearward end to support the rear ends of push rods 29 and urged by a spring 34 to move the post 33 to the right, Figure 2. Directly to the rear of the ends of push rods 29 is a field of stop pins 35 settable, as shown in Figure 3, by push rods 29 into the path of tail pins 36 to control printing and register entry in the manner shown by the above Sundstrand patents.

Movement of the push rods into register with successive rows of stops 35 as the keys 10 are depressed is under control of an escapement mechanism similar to that of the above Sundstrand patents and includes a bail pivoted on stud 21. The bail comprises top and bottom levers 39 and a post 40 connected between them, spring 27 positioned above spring 23, Figure 2, urging the bail clockwise to hold post 40 against rearward extensions of all the levers 26 so that the bail will be rocked when any key 10 is depressed. Connected to the top plate 39 is a push rod 41 passing through post 33. The swinging arm 30 is held against the tension of its spring 34 by a notched arm 42 pivoted on a stationary part and having pivoted thereto a lever 43. A spring 44 connected to the left end of lever 43 urges notched arm 42 and lever 43 against post 33 in a kind of scissors grip. When push rod 41 is moved rearwardly as a result of a key depression it pushes arm 42 rearwardly to release it from post 33 and to arrest movement of the post by catching in the notch of arm 42. When push rod 41 is retracted, post 33 is free to settle in the next notch of arm 42 wherein the push rods 29 are aligned with the succeeding row of stop pins 35 to the right.

In the mechanism thus far described, it will be evident that restoration of the parts is the only function performed after a key is depressed. To permit such restoration as soon as a key has performed its function, the following structure is provided. Referring to Figures 2 and 3, it will be noted that square stud 25 on slide 20 is positioned in front of the right arm of lever 26 and that the tail of slide 20 is formed with a cam edge 47. During the depression of a key 10, the rear ward movement of slide 20 rocks its lever 26 to set a stop pin 35 and through bail 39 to release post 33 from notched arm 42. Further depression of a key 10 moves slide 20 to engage comb 19 with its cam edge 47 so that a slight additional rearward movement of slide 20 shifts the square stud 25 thereon to the right and out of engagement with the operated lever 26. Springs 23 and 27 thereupon restore bail 39 and lever 26 to their unoperated positions. A second key 10 may now be depressed before the first key 10 has started its return or even if it is retained depressed.

When a key 10 is released, the associated spring 23 and lever 22 which retains a cam edge on its right end in engagement with stud 25 at all times, as shown in Figure 3, restores the key 10, bail 16, and slide 20 to the normal positions with stud 25 forward of lever 26.

It will thus be apparent that the above described keyboard mechanism enables a substantially more rapid operation of the keys of an adding machine than has previously been possible. It will also be apparent that the preferred embodiment of the invention as described above is susceptible of substantial modifications and variations without departure from the spirit of the invention.

What is claimed is:

1. A machine of the class described having a set of numeral keys, indexable stop members and key operable members interposed between said keys and said stop members, said key operable members comprising, for each key, a member driven at one end by said key, stationary means to guide the other end of said driven member for longitudinal movement, a stop member indexing device abutting the other end of said driven member and cooperative parts on said stationary means and said driven member to move said driven member out of abutting relation with said indexing device after said indexing device has indexed an aligned stop.

2. A machine of the class described having a set of numeral keys, indexable stop members, key operable members interposed between said keys and said stop members, and an escapement mechanism operable to control relative movement between said stop members and said key operable members, said key operable members including, for each numeral key, a member driven at one end by said key and a stop member indexing device abutting the other end of said driven member, means common to all said indexing devices to release said escapement mechanism to a partially released position upon operation of any indexing device, stationary means to move each key driven member from engagement with the abutting indexing device at the end of indexing movement of said indexing device and means to restore an operated indexing device and said escapement releasing device to normal positions when released from said driven member.

3. A machine of the class described having amount keys, slidable members each operable by one of said amount keys, an abutment on each slidable member, an indexing device engageable by each said abutment for operation by each slidable member, indexable stop means settable by said indexing devices during movement thereof in one direction, a stationary member to move each said slidable member from engagement with its indexing device after said stop means is indexed thereby, restoring means to return each indexing device to a normal position free of said stop members when released from said slidable member and means to restore an operated slidable member into abutting relation with its indexing device upon release of the operated key.

4. An indexing mechanism for a machine of the class described comprising a plurality of numeral key means, a slidable member connected to each key means, a plu rality of settable stop pins, stop pin setting members normally abutting said slidable members and operable thereby, and stationary means cooperative With each slidable member during its operation by a connected key means to disconnect said slidable member from the setting member driven thereby and means to restore said setting member to a normal position after its release from the slidable member.

5. An indexing mechanism for a machine of the class described comprising a plurality of numeral key means, a slidable member connected to each key means, a plurality of settable stop pins, stop pin setting members normally abutting said slidable members and operable thereby, and stationary means cooperative with each slidable member during its operation by a connected key means to disconnect said slidable member from the setting member driven thereby, means to restore said setting member to a normal position after its release from the slidable member, an escapement mechanism to control relative movement between said stop pins and said setting members, means common to said setting members to operate said escapement mechanism, and yieldable means to return each slidable member into driving engagement with its setting member upon return of the key means and slidable memberto normal position,

No references cited. 

